First let me put the disclaimer: I am aware that lineups get switched around in practice often, that there are countless lineup combinations that appear. But, they most definitely do run "1s vs 2s" at some points, and a recent Graham Couch interview with Tre Holloman basically confirmed they have been running 1s vs 2s already at least a little bit. 

Using pictures from practice posted on social media, and interviews to back up the pictures, I have reason to believe I know who the "2nd Team" is right now:

Fears

Holloman

_____

Booker

Cooper

Holloman said in the aforementioned interview that Izzo is playing Fears at the 1 and him at the 2. A picture posted today on the MSU Basketball official account shows Holloman, Booker, and Cooper in white while Walker is in green. This would also support the statement by Holloman.

The only position we don't know in the 2nd lineup is the 3. If we assume that Hoggard/Walker/Akins/Sissoko are all 1st team right now(safe assumption imo), and Malik Hall is not practicing fully yet, that leaves Normand and Carr as the two names not verified. It makes most sense to me that Carr would be playing the 4 in the 1st team right now, and Normand the 3 in the 2nd team. But, it is very probable -even likely- that the 4 spot in the 1st team is a rotating door right now. 

Again, this is all prospective, based on anecdotal evidence. Things are fluid, and Malik Hall will certainly be heavily in the mix when he is back to 100%.